1. Field of the Invention
The invention relates generally to signal processing systems and methods, and more particularly, to a system and method for processing image signals.
2. Description of the Related Art
The trend toward upsizing and higher resolution of display devices is ever increasing in recent years. With such trend of display device advancement, the demand has also grown for improving the capabilities of encoding processing and decoding processing of the images to be displayed on display devices (see, for example, Japanese Unexamined Patent Application Publications No. 2001-346201, 2004-356857, 2008-54183, and Heisei 10 (1998)-234043). In order to improve the processing capability of MPEG (moving picture experts group) decoder, for example, it is necessary to increase computing power of the processing unit for carrying out decoding processing, and also increase the bandwidth (transmission capacity) between external memories for storing decoded screen data. In addition, for improving the processing capability of MPEG encoder, it is necessary to increase the computing power of encoding processing unit for implementing the encoding processing, also to increase the bandwidth of transmission between external memories for storing encoded screen data.
In particular, with the block code in which encoding is carried out within frame such as in MPEG4 Studio Profile, when the encoding processing and decoding processing are further carried out on video signals with large image size such as 4K video signals, the codec processing has to be implemented at high speed. FIGS. 1 and 2 are drawings for illustrating the structure of a related art signal processing system for implementing encoding processing and decoding processing of video signals with large image size.
Although the details of the related art signal processing system 10 shown in FIGS. 1 and 2 will be described later on, it is explained herein briefly. With the related art signal processing system 10, image data are stored once in a frame memory 12, and thus stored data are subsequently distributed to plural local encoders 13a to 13d in units of frame. The image data encoded by the local encoders 13a to 13d are stored in a stream memory 15, arranged into the order of frame, and recorded on a record medium 16. As a result, since it is necessary for each of the local encoders to implement the encoding processing at a rate only once to four frames, the speed of the processing can be reduced.
In the case of reproducing video images, the image data read from the record media 16 are stored in the stream memory 15, and the stored data are distributed to plural local decoders 17a to 17d in units of frame. The image data decoded by the local decoders 17a to 17d are stored in the frame memory 15, arranged into the order of frame, and outputted as baseband signals.